This invention relates in general to sound attenuating partitions and in particular to sound attentuating or acoustical doors.
In the modern environment of increasing noise pollution, sound abatement has become an important consideration in both living and working quarters. To insulate against sound transmission from one area to another, a partition such as a conventional wall can act as a sound barrier. Generally, a more massive partition has a higher transmission loss. However this brute-force approach is not usually practical and is expensive.
Even with an adequate sound attenuating partition, a door installed in the partition presents a further opportunity for acoustical transmission from one side to the other. A door with a lower transmission loss can greatly depreciate the overall transmission loss of the partition. Accordingly, massive and expensive doors have been employed to minimize acoustical leakage. However, in most instances, it is both expensive and impractical to have doors as massive as the partitions.
Thinner and lighter weight doors, in particular ones with one and three quarters inch thicknesses are more standard in the building and construction industry. Acoustical doors of that thickness have been designed using high density materials such as metals (as disclosed in U.S. Pat. Nos. 3,319,738; 3,295,273) or chemically impregnated vinyl (as disclosed in U.S. Pat. No. 4,045,913) to achieve the performance level of the thicker more massive doors. However these prior art designs are still based on the principle of a massive sound barrier and therefore remain expensive to manufacture and relatively heavy.